Sliding door operating mechanism



2 Sheets-Sheet 1 l I /0// Wz B. B. BIDELMAN ETAL SLIDING DOOR OPERATINGMECHANISM l 1 I l l I l I i I l .ll

April 23, 1968 Filed March 11, 1966 INVENTORS .B/qBmflI/e/zan r 77 6 RAli/ar a N HU il/l/l/l/l/l/l 7 /Z K B/uced 0 mar; Geor ATTORN E1lLl/l/l/ //X 36 J6 J6 i5 /3 April 23,1968 B. B. BIDELMAN ETAL 3,378,952

SLIDING DQOR OPERATING MECHANISM Filed March 11, 1966 2 Sheets-Sheet 2NFQ Q Q R 9 Q w 9w w L 5 T Q W W m m Q Q @Nw o Q V w \m r a s \m w QMQ Qkw v Q 3 Q Q 6 w I m m ATTORNEY H10 ammw I mm WBRM% KH I. MW/ Z J ma i aw R wR 2 United States Patent 3,378,952 SLIDING DOOR OPERATING MECHANISMBruce B. Bidelman, Marshall, Raymond R. Martin, Albion, and George R.Millard, Tekonsha, Mich., assignors to Ronan & Kunzl, Inc., Marshall,Mich.

Filed Mar. 11, 1966, Ser. No. 533,503 16 Claims. (Cl. 49-360) Thisinvention relates to improvements in sliding door operating mechanism.The principal objects of this invention are:

First, to provide reciprocable drive mechanism for a sliding door inwhich the inertia forces incident to starting and stopping the door arecushioned to relieve the driving motor and mechanism from heavy impactloads.

Second, to provide yieldable door retarding members at the ends of theopening and closing motion travel of the door which cooperate with thedriving mechanism to prevent excess loads from being applied to thedriving motor and which yieldably cushion the stopping action of thedoor without imparting any reverse motion to the door such as would tendto move the door slightly from its opened or closed position.

Third, to provide a door supporting and travel limiting mechanism for asliding door in which yieldably mounted brake shoes cushion the travelmovement of the door and also actuate limit switches for de-energizingthe power source for the door operating mechanism.

Fourth, to provide reciprocable driving mechanism for a power operatedsliding door which is relatively inexpensive and easily adapted to doorsof different widths and lengths of opening and closing motion.

Fifth, to provide reciprocable door operating mechanism for a slidingdoor which inherently opens at maximum velocity and which tends to closemore slowly.

Sixth, to provide a door operating mechanism which includes a simplemechanical safety disconnect to prevent the door closing upon a personwith suificient force to injure the person.

Seventh, to provide a reciprocable door operating mechanism with motioncushioning brakes operative at the ends of the travel of the door, whichbrakes are automatically released by reverse starting motion of the doorin either direction to relieve the driving mechanism of any loadincident to overcoming the effect of the stopping brake.

Other objects and advantages of the invention will be apparent from aconsideration of the following description and claims. The drawings ofwhich there are two sheets illustrate a highly practical form of theoperating mechanism as applied to a horizontally sliding vertical door.

FIG. 1 is a fragmentary elevational view of a door mounted in a dooropening and adapted to be moved between open and closed position byoperating mechanism of the invention.

FIG. 2 is a fragmentary top plan view of the operating mechanism shownin two sections and taken along the plane of the line 2-2 in FIG. 1.

FIG. 3 is a front elevational view of the operating mechanism, the viewbeing broken into two sections and the driving motor being removed.

FIG. 4 is a vertical cross sectional view through the driving mechanismtaken along the plane of the line 44 in FIGS. 1 and 2.

FIG. 5 is a fragmentary enlarged vertical cross sectional view takenalong the plane of the line 55 in FIG. 4 and illustrating the supportingand braking and control mechanism adjacent the closing edge of the doorwith the door in closing motion.

FIG. 6 is a view of the mechanism shown in FIG. 5 with the door slowingand approaching closed position.

FIG. 7 is a view similar to FIGS. 5 and 6 showing the door at the startof its opening motion.

FIG. 8 is a fragmentary detailed elevational view of the connectionbetween the door operating mechanism and the movable support for thedoor.

As appears in FIG. 1 a door 1 is mounted for horizontal sliding motionin a wall 2 to open and close the doorway formed by the frame members 3.The door slides into or behind the wall 2 to the open position indicatedat 1A and is driven by means of mechanism of the invention which may beenclosed in the wall or within an upper lintel housing 4 extendingacross and beyond the doorway.

The door supporting mechanism consists of a door supporting trackindicated generally at 5 in FIG. 4 and including an upper structuralsupport 6 in the form of an angle shaped member and a lower channelshaped portion 7 secured to the upper angle as by bolts 8. The channelportion 7 has inwardly turned opposed lower supporting flanges 9 whichreceive and support pairs of rollers 10 10 mounted on cross pins oraxles 11. Two pairs of the rollers 10 are provided, one near the closingedge of the door and one near the opposite edge of the door. The rollersare connected by a door support bar 12 which projects downwardly betwenthe flanges 9 and is provided at each end with a pair of depending ears13 spaced longitudinally of the bar. The upper edge of the door 1 isprovided with hanger brackets 14 with upstanding lugs 15 projectingbetween the pairs of ears and secured thereto by cross pins 16.

Secured to the end of the supporting track corresponding to the openposition of the door is a mounting bracket or housing 17 (see FIGS. 2and 3) which supports a drive shaft 18 transversely of the track. Thedrive shaft 18 carries a drive pulley 19 in closely spaced relation tothe track and a reversible electric motor 20 operating through a gearbox 21 are conventionally illustrated and mounted in driving relation tothe shaft 18 adjacent to the track.

The pulley 19 reversely drives a flexible belt 22 and in the exampleillustrated the belt and pulley are of the V-belt type. The belt 22 isformed into a loop extending longitudinally of the track and trainedaround an idler pulley 23 positioned intermediate the ends of the track.The idler pulley is carried by a pin or axle 24 supported in an upwardlyfacing channel shaped idler pulley bracket 25 positioned or supported onthe lower horizontal flange 26 of the structural angle portion 6 of thetrack. The bracket slides on the flange 26, being guided by bolts orpins 27 projecting upwardly from the flange 26 through slots 28 in thebracket 25 to longitudinally guide the ends of the bracket. The rightend of the bracket has a cross wall 29 through which a guide pin 30 (seeFIG. 3) is slidably extended. The guide pin 30 is fixedly connected toan angle bracket 31 secured to the flange 26 and has adjustable stops ornuts 32 thereon which form abutments for a compression spring 33positioned around the pin and bearing against the crosspiece 29.

As will be apparent any unusual tension in the belt 22 will compress thespring 33 thus relieving the tension and releasing the frictionaldriving engagement between the belt and the drive pulley 19 so that thedoor will stop even if the motor 20 continues to operate. In theparticular example illustrated the belt is formed into a loop having anupper idling reach 34 and a lower driving reach 35 by connecting theends of a straight length of belting by means of crimped connectors 36(see FIG. 8) which engage the ends of the belting and have ears 37 thatare overlapped and secured to each other and to the top of the bar 12 asby the cap screw 38. The lower driving reach 35 of the belt extendswithin the channel shaped portion 7 of the rail to the lower peripheryof the idler pulley 23 which projects downwardly through a slot 138provided therefor in the pulley support bracket, upper rail portion 6and lower rail portion 7.

Positioned adjacent each end of the track is a retarding brake shoe andlimit switch assembly indicated generally by the numeral 3h. Theretarding brake and switch assemblies are identical and reversed so thata description of one will be sufficient to an understanding of themechanism. Secured to the top of flange 26 is a retarding platesupporting bracket having longitudinally spaced upstanding cars 41 ateach end with downwardly turned flanges 42 at their outer sides. Thebracket plate 46 is secured to the track flange by a pair of upstandingstuds 43 passed through the bracket and having nuts 44 on their upperends which compress brake or retarding springs 45 to yieldably urge thebrake shoe supporting brackets toward the track flange 26. The retardingplate supporting brackets are fixed by the studs 4-3 againstlongitudinal motion on the track. Supported between the upstanding ears41 and their downturned outer flanges 42 are cam pins 46 which extendthrough and longitudinally and vertically guide a generally rectangularbrake shoe plate 47. The plate 47 has cam slots 48 formed therein whichreceive the pins 46 and which are inclined upwardly or away from thetrack and toward the center of the track. As appears more clearly inFIG. 7 the cam slots 48 have longitudinal dwell portions 49 at theirinner ends which receive the pins 46 at one limit of travel of the brakeshoe. The brake shoe has a longitudinally inwardly facing cam surface 59positioned to engage and camming- 1y coact with the door supportingrollers 19 so that motion of the door and its rollers against the brakeshoe presses the brake shoe upwardly. The brake shoe or plate 47 isbiased longitudinally outwardly and downwardly toward the end of thetrack by a light tension spring 51 anchored to the plate by the screw 52and having its other end connected to the outer stud 43.

Positioned longitudinally inwardly of each brake shoe support bracket isa limit switch mounting bracket 53 having a bottom flange 54 secured tothe flange 26 of the structural angle portion of the track and having anupturned flange 55 on which is mounted an electrical switch 56 having anoperating roller or element 57. The flange 54 of the switch bracket isslotted as at 58 in FIG. 2 to pass a trip finger or switch actuatingportion 59 formed on the inner end of the brake shoe. Upward movement ofthe brake shoe under the influence of the door rollers away from theroller supporting flanges 9 moves the brake shoe and the shoe supportingbracket against the compression of the retarding spring means 45 andalso actuates the limit switch 5-6. While in the example illustrated thebrake shoe and brake shoe supporting bracket are mounted verticallyabove the track it will be apparent that other angular positions of thebrake shoe and switch mechanism relative to the axis of the track arepossible.

FIGS. 5, 6 and 7 illustrate the action of the retarding shoe on thedoor. In FIG. 5 the roller it) is rotating and the bar 12 is moving thedoor toward closed position. The switch actuating finger 59 is down andthe actuating element 57 of the switch is in unactuated position. Theshoe 47 is drawn longitudinally outwardly of the track and the pins 46are positioned in the keeper or dwell portion 49 at the inner ends ofthe slots 48. As the edge of the door approaches its stop position suchas the jamb indicated conventionally at 60 the roller moves the brakeshoe upwardly causing the finger 59 to actuate the switch. Beingvertically obstructed by the dwell portions 49, upward motion of theshoe lifts the pins 46 causing the brake shoe supporting bracket 40 tobe raised against the compression of springs 45 thus applying brakingpressure to the roller 18. The roller it) accordingly slides rather thanrotates between the brake shoe and its supporting flange 9 applying aretarding pressure which slows the door and prevents a heavy impactagainst the jamb. Note that the position of the pins in the keeperportion 49 prevent any reverse camming action which would tend to openthe door once it is stopped by the jamb 60. When the door is nextactuated toward open position as is shown in FIG. 7, the frictionalforce of the roller 19 on the bottom of the brake shoe moves the brakeshoe 47 with it longitudinally to the right causing the plate and itsinclined cam slots 48 to move up on the pins. This immediately releasesthe door retarding pressure on the roller and the door starts easilytoward open position. This reduces the starting load on the motor 26.The same action occurs with both brake and limit switch assemblies 39 atthe ends of the travel of the door.

It is pointed out that the lower working reach 35 of the belt is underdirect tension between the drive pulley l9 and the connection 38 to thedoor when the door is opened, the spring 33 having moved the idlerroller to initially tension the entire belt. The entire output of thedrive roller is thus available to quickly start the door in its openingmotion. Should the inertia of the door apply sufiicient tension to theidler support bracket 25 the spring 33 may yield slightly and thus aidthe motor in picking up the opening load of the door. As was previouslynoted the closing motion of the door is effected by tension in the upperreach 34 of the belt loop so that any obstruction such as might becaused by a person stepping into the path of the moving door will applytwice the closing tension of the belt to the idler pulley 23 so that thespring 33 is compressed and the frictional driving engagement of thebelt with the driving pulley is released. The drive to the door thusincorporates an automatic safety feature preventing injury to personsusing the door.

The limit switches 56 may be connected with the motor along with anothercontrol switch such as a switch mat 61 in a well known manner to causethe door to open and close as desired. While the operating mechanism forthe door has been shown as associated with the upper edge of a suspendeddoor, the brake and automatic stopping features of the operatingmechanism are equally applicable to drive connections positioned at thebottom of the door.

What is claimed as new is:

1. Sliding door operating and supporting mechanism including a doorsupporting track to support a door in open and closed positions relativeto an upright jamb, rollers spaced along said track and connected to thetop of the door, a drive shaft extending transversely of said trackadjacent an end thereof and having a reversible drive including a motorconnected to the shaft,

said mechanism being characterized by a drive pulley connected to saidshaft,

an idler pulley support longitudinally slidably mounted on said trackand having an idler pulley rotatably mounted on said pulley support,

first spring means biasing said support and idler pulley away from saiddrive pulley,

a belt trained around said pulleys and urged to frictional drivingengagement with said drive pulley by said first spring means,

means connecting a reach of said belt to the top of said door,

door opened and door closed retarding plates disposed in spaced relationalong said track to be engaged by one of said rollers in the opened andclosed positions of said door respectively,

retarding plate supporting brackets vertically movably mounted on saidtrack adjacent said retarding plates and spring loaded by second springmeans toward said track,

said supporting brackets being connected to said retarding plates toload said second spring means when one of said rollers engages one ofthe plates,

switch operating projections on said retarding plates,

and limit switches carried by said track and haivng operating elementspositioned to be actuated by said projections,

said switches being adapted to be electrically connected to said motorto stop the motor in door opened and door closed positions.

2. Mechanism according to claim 1 in which said door is connected to thereach of said belt which is driven in tension upon opening motion ofsaid door.

3. Mechanism according to claim 2 in which said belt is of V-shapedcross section and said pulleys are cor responding V pulleys mounted onhorizontal axis,

and the lower reach of said belt is tensioned upon opening motion of thedoor.

4. Mechanism according to claim 1 in which said retarding plates arelongitudinally slidably mounted on said brackets,

means limiting the sliding motion of said plates along downwardly andlongitudinally outwardly directed paths toward the ends of said track,

and third spring means biasing said plates outwardly toward the ends ofsaid track.

5. Mechanism according to claim 2 in which said retarding plates arelongitudinally slidably mounted on said brackets,

means limiting the sliding motion of said plates along downwardly andlongitudinally outwardly directed paths toward the ends of said track,

and third spring means biasing said plates outwardly toward the ends ofsaid track.

6. Mechanism according to claim 4 in which said means limiting thesliding motion of said plates on said brackets have end portions attheir longitudinally inner ends preventing vertical motion of the platesrelative to the brackets and into which said plates are biased by saidthird spring means.

7. Mechanism according to claim 5 in which said means limitin thesliding motion of said plates on said brackets have end portions attheir longitudinally inner ends preventing vertical motion of the platesrelative to the brackets and into which said plates are biased by saidthird spring means.

8. Sliding door operating and supporting mechanism including a doorsupporting track to support a door in open and closed positions relativeto an upright jamb, rollers spaced along said track and connected to theedge of the door, a drive shaft extending transversely of said trackadjacent an end thereof and having a reversible drive including a motorconnected to the shaft,

said mechanism being characterized by a drive pulley connected to saidshaft,

an idler pulley mounted on said track,

a drive member loop trained around said pulleys,

means connecting a reach of said drive member loop to said door,

and door opened and door closed retarding means disposed in spacedrelation along said track to be frictionally engaged by parts carried bythe door in approaching the opened and closed positions of said doorrespectively said retarding means having springs loaded as the partsapproach open and closed positions of the door, said springs beingreleased by initial movement of the parts on the door away from openedand closed positions of the door.

9. Mechanism according to claim 8 in which said retarding meanscomprises,

retarding member supporting brackets mounted on said track for movementtoward and away from the track, first spring means biasing said bracketstoward said track,

and retarding members mounted for camming movement on said bracketslongitudinally and transversely of said track and spring loaded bysecond spring means toward said track.

10. Mechanism according to claim 9 in which said retarding membersupport brackets and said retarding members are mounted for movement inplanes generally parallel to the plane of said drive member loop.

11. Mechanism according to claim 10 in which said belt is connected tothe upper edge of said door.

12. Sliding door operating and supporting mechanism including a doorsupporting track to support a door in open and closed positions relativeto an upright jamb, rollers spaced along said track and connected to theedge of the door, a drive shaft extending transversely of said track andhaving a reversible drive including a motor con nected-to the shaft,

said mechanism being characterized by a drive pulley connected to saidshaft,

an idler pulley support longitudinally slidably mounted on said trackand having an idler pulley rotatably mounted on said pulley support,

spring means biasing said support and idler pulley away from said drivepulley,

a flexible driving loop trained around said pulleys and urged tofrictional driving engagement with said drive pulley by said springmeans,

means connecting a reach of said driving loop to said door,

limit switches having operating elements positioned to be actuated bymovement of said door to open and closed positions and adapted to be.connected to said motor,

a retarding plate support bracket fixedly located adjacent said track,

a retarding plate movably connected to said support bracket andpositioned to be cammingly engaged by one of said rollers as said doorapproaches closed position,

second spring means biasing said retarding plate against camming motionby said one roller,

means forming a cam connection between said retarding plate and saidsupport bracket and arranged to permit disengaging motion of said platefrom said one roller upon opening motion of said door,

and third spring means biasing said plate on said bracket toward rollerengaging position.

13. Mechanism according to claim 12 in which said means forming said camconnection has a dwell portion at one end to which said plate is urgedby said third spring means.

14. Mechanism according to claim 12 in which the operating element ofone of said switches is positioned to be actuated by said retardingplate upon movement of the plate by said roller against said secondspring means.

15. Sliding door operating and supporting mechanism including a doorsupporting track to support a door in open and closed positions relativeto an upright jamb, rollers spaced along said track and connected to theedge of the door, a drive shaft extending transversely of said track andhaving a reversible drive including a motor connected to the shaft,

an idler pulley mounted in spaced relation to said drive pulley alongsaid track,

a flexible driving loop trained around said pulleys,

means connecting a reach of said driving loop to said door,

limit switches having operating elements positioned to be actuated bymovement of said door to open and closed positions and adapted to beconnected to said motor,

a retarding plate support bracket fixedly located adjacent said track,

a retarding plate movably connected to said support bracket andpositioned to be cammingly engaged by one of said rollers as said doorapproaches closed position,

spring means biasing said retarding plate against camming motion by saidone roller,

means forming a cam connection between said retarding plate and saidsupport bracket and arranged to permit disengaging motion of said platefrom said one roller upon opening motion of said door,

7 and second spring means biasing said plate on said 2,804,296 brackettoward roller engaging position. 2,937,867 16. Mechanism according toclaim 15 in which said 3,043,584 cam connection has a dwell portion atone end to which 3,18Q,63 5

said plate is urged by said second spring means. 5

References Cited UNITED STATES PATENTS 2,803,454 8/1957 Tatro 4928 X 8Raqu 49138 Schweig 49138 X Kiel'horn 49--138 Miller 49138 X DAVID J.WILLIAMOWSKY, Primary Examiner.

J. KARL BELL, Assistant Examiner.

8. SLIDING DOOR OPERATING AND SUPPORTING MECHANISM INCLUDING A DOORSUPPORTING TRACK TO SUPPORT A DOOR IN OPEN AND CLOSED POSITIONS RELATIVETO AN UPRIGHT JAMB, ROLLERS SPACED ALONG SAID TRACK AND CONNECTED TO THEEDGE OF THE DOOR, A DRIVE SHAFT EXTENDING TRANSVERSELY OF SAID TRACKADJACENT AN END THEREOF AND HAVING A REVERSIBLE DRIVE INCLUDING A MOTORCONNECTED TO THE SHAFT, SAID MECHANISM BEING CHARACTERIZED BY A DRIVEPULLEY CONNECTED TO SAID SHAFT, AN IDLER PULLEY MOUNTED ON SAID TRACK, ADRIVE MEMBER LOOP TRAINED AROUND SAID PULLEYS, MEANS CONNECTING A REACHOF SAID DRIVE MEMBER LOOP TO SAID DOOR, AND DOOR OPENED AND DOOR CLOSEDRETARDING MEANS DISPOSED IN SPACED RELATION ALONG SAID TRACK TO BEFRICTIONALLY ENGAGED BY PARTS CARRED BY THE DOOR IN APPROACHING THEOPENED AND CLOSED POSITIONS OF SAID DOOR RESPECTIVELY SAID RETARDINGMEANS HAVING SPRINGS LOADED AS THE PARTS APPROACH OPEN AND CLOSEDPOSITIONS OF THE DOOR, SAID SPRINGS BEING RELEASED BY INITIAL MOVEMENTOF THE PARTS ON THE DOOR AWAY FROM OPENED AND CLOSED POSITIONS OF THEDOOR.